A substitute for going to culinary school? Is there

I find that anything Cooks Illustrated puts out usually has a decent list of "whys" and have been garnering them up over the years. Unfortunately this can leave you something of a specialist with deep knowledge on whatever their articles cover, but if you want to learn the why of something, they are a great source.

For baking in particular Ratio is an excellent book.

Khymos is a fantastic resource, and has probably the best collection of recipes out there at the moment.

There's also a lot of good stuff at the French Cullinary Institute's Cooking Issues blog. They've got a good post on hydrocolloids that's quite enlightening.

I actually disagree on the McGee recommendations. While it's an excellent book, full of great info, I don't think it's a good starting point for molecular gastronomy (in the sense of the cooking movement rather than the more literal sense)